Drum



C. H. STRUPE Oct. 5, 1943.

DRUM

Filed July 10, 1942 2 Sheets-Sheet 1 amzmr Oct. 5, 1943.

c. H. STRUPE 2,331,096

DRUM

Filed July 10, 1942 2 SheetsShet 2 Patented Oct. 5, 1943 UNITED STATES PAT ENT OF F-l-CE DRUM Cecil H..Strupe, Chicago, 111., assignor to W. F. .L.

Drum.Co., Chicago, 111., a copartnership com.- pri'sihg. William FILudwig, William F. Ludwig, Jr;, Elsa M. Ludwig, and himself Application-m1 10,1942, Serial No. 450,374 Claims. (01. 84411) This invention. relates, to improvements in drums and more particularly to means for tensioning the heads of drums simply; cheaply; and emciently;

A-main object of the'invention is to provide a' drumwhereinthe amount of metal usedis minimizedto the utmost possible degree without sacrifice. of any essentially desirable or'necessary means. required for the proper tuning ofthe view, similar to;Fig;.3, showinganother form of embodiment .of the invention.

In; the instance illustrated. the cylindrical drum casing Iris composed ofp'wood of a;suitable; type. Secured rigidly toi-the'inneriace of said casing; at its respective end portions, is a pairof .hoops 2, also of wood, havingtheir outer: edges disposedsubstantiallyfiush with the ends of the casing I.

A-pairof outer hoopsB-issupplied. to which the marginaledge portions of'the'drum heads 4 are suitably secured and which are movable l'ongitudinally of the casing I and are normally spacedappieciably from the ends of said casing.

A second outer pair of hoops 5 is disposed telescopically of the marginal portions of the heads 4 upon opposite end portions of the casing with a portion of each thereof projecting beyond the ends of the casing I, the inner edges of said hoops bearing upon the hoops 3 to prevent the latter from moving toward the ends of the cas ing responsively to tension of the heads 4. Tllt hoops 5 are rigidly secured to the casing I in any suitable manner as by means of screws 6 which pass through the marginal portions of the heads 4 and engage in the casing and the hoops 2, or by means of the links 1 shown in Fig. 4

which are secured to the casing I inwardly of the hoops 3 by means of screws 8 and at their outer end portions to the hoops 5 in any suitable manner. An advantage of the links I is that the puncture of the skins 4 is avoided.

Another pair of hoops 9 is disposed telescopically within the hoops 2 with their outer edge portionsinengagement with the heads-42 Each. of said hoops 9 is equipped with an inwardly projecting, preferably annular, shoulder'iormation I0, disposed angularly to the plane of. its

outer edge to define anundercut or groove. for.- mation in which the outer ends ofbowed. springs- II engage an are held against becoming disenigaged when said springs are slack.

In the instance illustrated, thesprings I=I1arex composed of resilient strips of wood and are equally spaced apart, the number thereof being such that the portions of the hoops Qbridging the spaces betweenthe springs I I will support the pressure of heads 4' when'said hoops are forced:

outwardly to tension said heads.

Each of the springs II is backed by. a rein.-

forcing strip or. spring element I2: uponwhichr there is mounted rigidly a nut I3- of suitable shape in which the threaded end portion of a latter, the headof'said screw being equipped-with; a'key engaging formation for rotation by such.

key. to effect flexing of the springs II and I2 to increase. its normal radius and thus force the."

hoops 9 outwardly to tension the heads 4 andv to permit. the. springs to restore themselves to a:

curvature which tension on heads is relieved, it-

being: obvious that such return of the springs-to. smaller radius will be aided by the pressure'oi.

heads 4 transmitted to the ends of the springs I I through the hoops.

It will be observed that the set-screws I I are purely tension elements which are held at the inner limit of movement by the tension of the springs. Said screws are so loosely engaged at their head end portions in the washers I5 and openings in the casing I aligned therewith that they may swing slightly laterally of their normal positions to accommodate themselves to any slight changes in the positions of the nuts I3 incident to variations in degree of movement of the respective hoops 9 due to greater degree of yield of one of the heads 4 to pressure of a hoop 9 than the other of said heads 4.

The inner end of each of the screws I4 is equipped with a fixed collar I6 or equivalent stop formation to prevent the same from being disengaged from the nut through which it passes or from being moved outwardly far enough to al- The latter are held suitably against? low the ends of the spring H which it controls from becoming disengaged from the hoops 9.

The drum illustrated is shown as equipped with a set of snares and a snare tensioning means which may be of any desired type constituting no part of this invention.

I claim as my invention:

1. A drum comprising a cylindrical casing, a pair of hoops slidably mounted upon the the outer surface of said casing in spaced relation to the ends thereof, a pair of drum-heads having their marginal edge portions secured to said hoops, a

pair of hoops secured to the end portions of the casing outwardly of and constituting stops for said first-named hoops, a pair of drum head tensioning hoops mounted within the end portions of the casing and equipped with opposed shoulder formations, a series of equally spaced apart flexible members disposed within the oasing and engaged at their ends with said shoulder formations, set-screws rotatably engaged with the casing midway of the ends of the latter against movement inwardly of the same, and nuts rigidly engaged with said members and having threaded engagement with the shanks of said set-screws, said members being adapted to become elongated as said screws are rotated to move the said nuts towards the casing and thereby force the last-named hoops outwardly to tension said heads.

2. A drum comprising a cylindrical casing, a pair of hoops slidably mounted upon the outer surface of said casing in spaced relation to the ends thereof, a pair of drum-heads having their marginal edge portions secured to said hoops, a pair of hoops secured to the end portions of the casing outwardly of and constituting stops for said first-named hoops, a pair of drum head tensioning hoops mounted within the end portions of the casing and equipped with opposed shoulder formations, a series of equally spaced apart bowed spring members disposed within the cas-' ing and engaged at their ends with said shoulder formations,set-screwsrotatahly engaged with the casing midway of the ends of the latter against movement inwardly of the same, and nuts rigidly engaged with said members between the ends thereof and having threaded engagement with the shanks of said set-screws, said members being adapted to be increased in radius as said set-screws are rotated in a direction to draw said nuts toward the inner face of the casing and thereby cause the ends of said members to move the last-named outwardly to tension the said heads.

3. A drum comprising a cylindrical casing equipped with a pair of reinforcing hoops mounted upon its inner end portions, external hoops slidably mounted thereupon, drum heads secured to said last-named hoops, a pair of external hoops mounted upon the ends of said casing and constituting stops for said last-named hoops, another pair of hoops disposed telescopically of the first-named pair and equipped with opposed shoulder formation, a series of equally spaced apart bowed springs engaged at opposite ends with said shoulder formations and maintaining 7 marginal edge portions secured to said hoops, a

pair of hoops secured to the end portions of the a casing, outwardly of and constituting stops for said first-named hoops, a pair of drum head tensioning hoops mounted within the end portions of the casing, and a series of adjustable springs engaged at their ends with the lastnamed hoops for projecting the same outwardly against the drum heads for tensioning the latter.

5. A drum comprising a cylindrical casing, a pair of hoops slidably mounted upon the outer surface of said casing in spaced relation to the ends thereof, a pair of drum-heads having their marginal edge portions secured to said hoops, a pair of hoops secured to the end portions of the casing outwardly of and constituting stops for said first-named hoops, a'pair of drum head tensioning hoops mounted within the endportions of the casing, a series of equally spaced-apart devices within the casing and engaged at their ends with saidtensioning hoops, and a series of tensioning screws engaged at their inner ends with said devices and at their outer ends with the casing and projecting'through the latter for actuation from the exterior thereof, the rotation of said screws in one direction acting to force the ends of said devices outwardly to cheat outward movement of the tensioning hoops to effect tensioning of said drum heads.

CECIL H. STRUPE. 

